JAC pp519-22 MW3063

Enterococci are isolated from 10–20% of cases of bacterial endocarditis and therapy generally consists of a combination of a penicillin or vancomycin plus an aminoglycoside. For the penicillins, data suggest that serum concentrations should be maintained above the MIC throughout the dosing interval to prevent the loss of efficacy, since no post-antibiotic effect has been observed for these agents against enterococci. Although the optimal dosing regimen for the penicillins has been described, the most appropriate administration schedule for the aminoglycosides remains controversial. In this study, we simulated the pharmacokinetic profile of once-daily and thrice-daily gentamicin regimens to determine their efficacy in combination with penicillin for the treatment of experimental Enterococcus faecalis endocarditis.